Apparatus and method for generating an aerosol

Abstract

The present invention is directed to improvements related to the generation of aerosols and outlines an apparatus and methods which supports deagglomeration and counteracts reagglomeration of aerosol particles. The apparatus is provided with an arrangement of inlet conduits for pressurized gas that promote transportation with a rotational flow towards an exit conduit. In order to further support production of high quality aerosols, the apparatus can be provided with an impactor aligned with the exit conduit with at least one impacting surface that minimizes formation of impact residues.

The invention claimed is: 
     
       1. An aerosol generating apparatus having a main axis of rotational symmetry and comprising:
 an at least partially spherical powder chamber for loading an aerosolizable a powder therein and mixing the aerosolizable powder with pressurized gas, the powder chamber having one or several compartments; 
 at least two inlet conduits connected to a pressure chamber and being operable to introduce the pressurized gas to the powder chamber by at least two inlet orifices of said at least two inlet conduits, respectively, and create a powder suspension in the pressurized gas in the powder chamber; and 
 an ejection conduit, the ejection conduit having an inlet from the powder chamber and opening at an exit orifice to an ambient pressure, the ejection conduit opening at the exit orifice being operable to form an aerosol when the powder suspension in the pressurized gas is released from the exit orifice, wherein 
 (i) each of the at least two inlet conduits has a symmetry axis extending into a respective projection line and the at least two inlet conduits are arranged to admit pressurized gas inlet flows in opposite directions; 
 (ii) the inlet conduit projection lines are equidistant to an inlet conduit parallel plane which contains the apparatus main axis of rotational symmetry; 
 (iii) the inlet conduit projection lines form acute angles with the apparatus main axis of rotational symmetry; and 
 (iv) the at least two inlet conduits have inlet orifices located in a spherical part of the at least partially spherical part of the powder chamber and operable to form a forward rotating flow of the powder suspension in the pressurized gas toward the ejection conduit inlet. 
 
     
     
       2. The apparatus according to  claim 1 , wherein the powder chamber comprises a substantially hemispherical compartment, comprising the at least two inlet orifices for pressurized gas. 
     
     
       3. The apparatus according to  claim 1 , wherein the powder chamber is spherical and wherein said inlet orifices are oppositely arranged in the powder chamber. 
     
     
       4. The apparatus according to  claim 1 , wherein the powder chamber further comprises a substantially cylindrical compartment and a substantially ellipsoid compartment. 
     
     
       5. The apparatus according to  claim 4 , wherein the substantially ellipsoid compartment comprises the ejection conduit. 
     
     
       6. The apparatus according to  claim 1 , wherein a distance between each of the conduit projection lines and the inlet conduit parallel plane is from about 0.01 to about 1 mm. 
     
     
       7. The apparatus according to  claim 1 , wherein the ejection conduit has a non-tapered abrupt inlet. 
     
     
       8. The apparatus according to  claim 1 , wherein the ejection conduit has a substantially uniform cross-section, substantially shaped as a cylinder. 
     
     
       9. The apparatus according to of  claim 1 , further comprising an impactor adapted to meet the aerosol powder discharged from the exit orifice. 
     
     
       10. The apparatus according to  claim 9 , wherein the impactor comprises an impactor body having an impacting surface and, between the impactor body and an impactor housing, an impactor channel is provided with a substantially ring-shaped shaped cross-section. 
     
     
       11. The apparatus according to  claim 1 , wherein the at least two inlet conduits are each substantially cylindrical, and the at least two inlet orifices are each an ellipsoid. 
     
     
       12. The apparatus according to  claim 10 , wherein the impactor body comprises a substantially cylindrical part and a conical part and wherein said conical part provides a primary impacting surface. 
     
     
       13. The apparatus according to  claim 12 , wherein the impactor further comprises a secondary impacting surface provided at a cylindrical inner surface of a cylindrical part of the impactor housing at an entrance of the impactor channel. 
     
     
       14. The apparatus according to  claim 12 , wherein the conical part is a recessed cone comprising a surface with a tangent having an angle with the main axis of rotational symmetry increasing with a cone radius, admitting substantially the same acute impact angle γ for each powder agglomerate meeting the impacting surface. 
     
     
       15. The apparatus according to any  claim 1 , comprising at least one additional inlet conduit with a projection line that intersects the inlet conduit parallel plane. 
     
     
       16. The apparatus according to of  claim 1 , further comprising a pressurized gas having a pressure of at least 50 bar in the pressure chamber.